Multiple users often collaborate on electronic files. These users often implement their own personal techniques for communicating what changes have been made across versions of a file. In some cases, users will use file-naming conventions to communicate information about the electronic file (e.g., naming a file with the date and/or user that last modified it). In other cases, users will communicate information through a third-party tool (e.g., email or instant messenger) to convey information about when a specific version of a file was created, or what has changed in a file. Some users use native features of the file itself to communicate this information. For example, some users utilize Microsoft Word's track changes feature to comment about what changes are being made by a particular user and when those changes were made. Other users manually inspect multiple versions of a particular file to determine what changes have been made to a file. These existing processes are cumbersome and require significant time investment by users to understand the changes that occur to a file over time. These processes make it difficult for users to restore a file to a particular previous version, because the user must manually review multiple sources of information in order to understand the contents of various versions of files.
Some users store content items with online content management systems. Such systems typically allow users to upload a content item to a server computer accessible via the Internet or another communications network. Users can access the content item from their personal computing device. One well-known online content management system is the Dropbox™ file hosting service provided by Dropbox, Inc. of San Francisco, Calif. Storing a content item with an online content management system allows users to back up, share, synchronize, access, and store their content items.
Multiple users may use an online content management system to collaborate on a content item. A version history in an online content management system allows users to view multiple versions of a content item over time, however, it only provides limited information about the changes made to versions of a content item over time and does not provide an easy way for users to preview and/or restore old versions of a content item.
The approaches described in this section are approaches that could be pursued, but not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated, it should not be assumed that any of the approaches described in this section qualify as prior art merely by virtue of their inclusion in this section.